title: Stimulation of growth hormone release by vasoactive intestinal polypeptide from human pituitary adenomas in vitro.
abstract: The effects of vasoactive intestinal polypeptide (VIP), TRH, dopamine, and rat median eminence extract on GH release from GH-secreting pituitary adenomas were studied in vitro using a sensitive superfusion method. Dispersed pituitary tumor cells obtained from three patients with acromegaly were placed in a superfusion column, and the amounts of GH in the superfusate were determined. The addition of VIP (10(-6) M) to the perfusion system resulted in a marked increase in GH release in all three cases, and a dose-response relationship in VIP (10(-8) 10(-6) M) induced GH secretion was observed in one case studied. TRH (10(-7) M) and median eminence extract (1 equivalent/ml) also caused an abrupt and marked increase in GH release in all of the experiments. The infusion of either dopamine (10(-7) M) or bromocriptine (10(-7) M) inhibited GH secretion. These results suggest that VIP as well as TRH stimulate GH secretion by a direct action on GH-secreting pituitary tumor cells in at least some acromegalic patients.
mesh_terms: D000236:Adenoma / Q000378:metabolism*; D000328:Adult; D004298:Dopamine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D005768:Gastrointestinal Hormones / Q000494:pharmacology*; D013006:Growth Hormone / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008473:Median Eminence / Q000502:physiology; D010477:Perfusion; D010911:Pituitary Neoplasms / Q000378:metabolism*; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology; D014020:Tissue Extracts / Q000494:pharmacology; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
chemical_list: D005768:Gastrointestinal Hormones; D014020:Tissue Extracts; D014660:Vasoactive Intestinal Peptide; D013973:Thyrotropin-Releasing Hormone; D013006:Growth Hormone; D004298:Dopamine